Membrane type coffee filters for drip through type coffee makers are well known, as set forth in U.S. Pat. No. 4,728,425, L. G. Sandvig, Mar. 1, 1988, for example, showing a typical cuplike coffee container for receipt of an open top substantially cup shaped membrane, generally paper, coffee filter. There is a problem with such open top filters, which must be disposed of after use, in that it is easy to spill coffee grounds in removing the filter cup and wet coffee grounds. Also, when such used filters are disposed of in a trash container, the unconfined coffee grounds are messy and tend to create unsanitary conditions.
U.S. Pat. No. 4,859,337, E. H. Woltermann, Aug. 22, 1989 teaches sealed filter units already filled with coffee. However, such prefilled units are expensive and may not permit the consumer to choose a preferred brand or grind, etc.
U.S. Pat. No. 4,981,588, J. Poulallion, Jan. 1, 1991 provides for a filter for support in a teacup for preparing a single cup open top and provides the same disadvantages heretofore discussed regarding disposal.
U.S. Pat. No. 3,833,125 H. A. Schwartz shows coffee filter elements of different shapes that fit over coffee baskets for percolators with axial stems that conform to a fit over a stem. One substantially square shaped embodiment has holes in the corner for threading over the stem after coffee grounds are added to provide filter layers above and below the coffee. This assembly must be removed wet after use and is subject to handling and the problems of spilling of coffee grounds and disposal heretofore discussed.
There is no satisfactory way of dealing with disposal of the used coffee grounds in open top cup shaped membrane filters, or the equivalent such as used in stem type drip cage containers.
Accordingly it is an object of this invention to resolve the problems of removal and disposal of open cup type membrane coffee filters after use.